Study: Proton treatment for prostate cancer results in few complications

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Journalists reporting on research coming from a nearby medical center need to scrutinize claims and not simply parrot copy from a news release. New technologies for prostate cancer are promoted all the time.

Our Review Summary

This story provides a very unbalanced look at one highly-promoted treatment option for men with prostate cancer. It reported on a talk given at a meeting (meaning that the information has not undergone rigorous peer review). Journalists need to understand that talks at scientific meetings may not be ready for prime time – especially not without any independent expert analysis. The story fell short on evaluating the evidence, on quantifying harms, and on giving context and comparisons with other approaches.

it was troubling to see large chunks of the story that seemed to come directly from a university news release.

Why This Matters

Men with a diagnosis of prostate cancer need to understand how various treatment options compare in men like themselves in order to make a decision that is right for them. There have been many new technologies in recent years (robots, cyberknife, proton beam) that are being aggressively marketed to patients with early-stage cancer despite limited evidence for their benefits and harms.

Criteria

Satisfactory

Adequate job. The story explained: "proton therapy is expensive for hospitals and for patients. It typically costs $100 million to build a proton treatment center and treatment may be $20,000 more expensive than conventional radiation treatments. That’s why the medical community is still debating whether the expense is worth it."

Not Satisfactory

The story did not include information about the percentage of men who appeared to be free of prostate cancer after treatment. Instead, the focus of the story was more on the percentage of men who did not experience the complications of complete incontinence or the majority of men who self-reported being sexually active after treatment. As noted in the "evidence" and "harms" criteria above, we just didn’t learn enough about the data.

Not Satisfactory

While mentioning the possible side effects of the chances of incontinence and impotence, the story didn’t give readers any sense of how often this happened.

It also failed to provide readers with a critical piece of information – what percentage of men receiving this treatment went on to have metastatic prostate cancer. Since this is the outcome the treatment is aimed at preventing, it is the potential harm that is key to evaluating its benefit. The story briefly alludes to men in the trial taking androgen deprivation therapy (ADT). Presumarly some of the ADT was provided along with radiation for high-risk patients (standard recommendation), but patients who needed ADT after treatment would represent treatment failures. Because no information is provided on the number of patients receiving ADT or the indications, it is difficult to interpret results. Sexually active does not necessarily mean having erections sufficient for intercourse–a standard metric–so this result is also difficult to interpret. Another issue is that the low-risk patients (definition not provided, number of patients not provided) might not have needed any treatment–active surveillance might have been appropriate for this group so that their "harm" could be overtreatment. Finally, 18 months may not be sufficient time to determine treatment complications–particularly sexual dysfunction–which may not appear for at least several years after radiation.

These are not merely academic concerns. They are issues a story should take into account before publishing a headline as a statement of fact: "Proton treatment results in few complications."

Not Satisfactory

The story reported on results of a study presented at a meeting without mentioning the nature of the study. A major problem with the study is the lack of a comparison group making it difficult to interpret the validity of the findings. Another problem is that the article (or perhaps investigators) did not report the proportion of men who were actually followed for 18 months. If the proportion was substantially less than 100% the results could be biased. Having poor outcomes is often a reason that subjects do not return for follow up.

Dropping back to the big picture, any story based on a talk at a scientific meeting, as this was one was, should include some discussion of the limitations of drawing conclusions from the talk. The work hasn’t undergone the same rigorous peer review as a paper submitted to a medical journal. In their paper, "Media Coverage of Scientific Meetings: Too Much, Too Soon?" — Woloshin & Schwartz recommend the following language for journalists who choose to write about preliminary unpublished research presented at meetings:

"The findings presented are a work in progress. Because the findings have not undergone final peer review, they have yet to be independently vetted, and may change."

There were no such caveats in this story. As you can see, it would only take about 25 more words to address this concern.

Not Satisfactory

Not Satisfactory

The story failed to provide information about how men similar to those in this proton beam case series fared when following a course of active surveillance or surgery or conventional radiation therapy to treat prostate cancer.

Not Satisfactory

While addressing the cost to hospitals for setting up the machinery to deliver ‘proton therapy’, the story did not discuss the current, rather limited number of facilities (about a dozen in place or in development in the US) that are equipped to provide this form of radiation.

So, while we acknowledge this is an Orlando paper reporting on a Gainesville center’s study, we still think it’s important for readers to know how limited is the availability of this approach – no matter where you live.

Not Applicable

Although erectile dysfunction after treatment can occur, complete impotence was rare and few were dissatisfied with their treatment choice. The results were reported by Dr. Bradford Hoppe, a radiation oncologist at the UF Proton Therapy Institute, during the 52nd Annual Meeting of the American Society for Radiation Oncology.

News release said:

Although erectile dysfunction after treatment can occur, complete impotence was rare and few were dissatisfied with their treatment choice. The results were reported by UF Proton Therapy Institute radiation oncologist Bradford S. Hoppe, M.D., during the 52nd Annual Meeting of the American Society for Radiation Oncology.

Story said:

At UF, where the patients were all treated at the UF Proton Therapy Institute, the clinical study includes 98 men with low-, intermediate-, and high-risk prostate cancer and who are 55 years old or younger. Patients were evaluated pre-treatment and post-treatment at six month intervals. Rates of reported side effects varied at the six-, 12- and 18-month intervals.

Eighteen months after treatment, the study found:

•21 percent of patients experienced mild urinary side effects that were treated with prescription medication

•3 percent experienced mild gastrointestinal side effects that were treated with prescription medication

•No patients experienced permanent incontinence

•No patients experienced significant rectal side effects

•94 percent of those who did not receive androgen deprivation therapy were sexually active

•Only 2 patients were dissatisfied with their treatment decision

The authors say that further study is needed to confirm findings.

News release said:

The clinical study includes 98 men with low-, intermediate-, and high-risk prostate cancer and who are 55 years old or younger. Patients were evaluated pre-treatment and post-treatment at six month intervals. Rates of reported side effects varied at the six-, 12- and 18-month intervals.

Results show that at 18 months following treatment:

• 21 percent of patients experienced mild urinary side effects that were treated with prescription medication,

• 94 percent of those that did not receive androgen deprivation therapy were sexually active,

• Only 2 patients were dissatisfied with their treatment decision.

Further study is needed in order to confirm findings

Total Score: 3 of 9 Satisfactory

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